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21 – 30 of 44Alfredo Canelas and Jean Rodolphe Roche
In this paper the authors review the recent numerical techniques proposed to solve the forward and inverse problems concerning the electromagnetic casting and electromagnetic…
Abstract
Purpose
In this paper the authors review the recent numerical techniques proposed to solve the forward and inverse problems concerning the electromagnetic casting and electromagnetic levitation techniques of the metallurgical industry. In addition, the authors present a new topology optimization method to solve the inverse axisymmetric electromagnetic levitation problem.
Design/methodology/approach
The proposed method is based on an exact second-order topological expansion of a Kohn–Vogelius-like functional specially devised for this problem.
Findings
Through some examples the authors show that it can find suitable solutions efficiently.
Originality/value
The new method completes the set of efficient methods available to solve the inverse electromagnetic casting and the inverse axisymmetric electromagnetic levitation problems.
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Soucheng OuYang, Yong Wu, Yi Lin and Chao Li
The discontinuity problem of general non‐linear evolutionary equations and the chaos of complex models of poly‐order are studied. The concept of “blown‐up” of Navier‐Stokes…
Abstract
The discontinuity problem of general non‐linear evolutionary equations and the chaos of complex models of poly‐order are studied. The concept of “blown‐up” of Navier‐Stokes equation is discussed, which was introduced by OuYang in 1994 and 1995. The results show that the blown‐up of the model appears during the whole evolution of general non‐linear equations; and that the concept of “chaos” of Lorenz’s model should be restudied questioningly.
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THE aim of this paper is to calculate the natural frequencies and to consider the influence of the damping parameter on a wing's natural flexural and torsional vibration. The…
Abstract
THE aim of this paper is to calculate the natural frequencies and to consider the influence of the damping parameter on a wing's natural flexural and torsional vibration. The author took into account only the elastic hysteresis of the material because the structural damping, depending on the type of the aeroplane, cannot be taken into account in a general consideration.
Elçin Yusufoğlu and Barış Erbaş
This paper sets out to introduce a numerical method to obtain solutions of Fredholm‐Volterra type linear integral equations.
Abstract
Purpose
This paper sets out to introduce a numerical method to obtain solutions of Fredholm‐Volterra type linear integral equations.
Design/methodology/approach
The flow of the paper uses well‐known formulations, which are referenced at the end, and tries to construct a new approach for the numerical solutions of Fredholm‐Volterra type linear equations.
Findings
The approach and obtained method exhibit consummate efficiency in the numerical approximation to the solution. This fact is illustrated by means of examples and results are provided in tabular formats.
Research limitations/implications
Although the method is suitable for linear equations, it may be possible to extend the approach to nonlinear, even to singular, equations which are the future objectives.
Practical implications
In many areas of mathematics, mathematical physics and engineering, integral equations arise and most of these equations are only solvable in terms of numerical methods. It is believed that the method is applicable to many problems in these areas such as loads in elastic plates, contact problems of two surfaces, and similar.
Originality/value
The paper is original in its contents, extends the available work on numerical methods in the solution of certain problems, and will prove useful in real‐life problems.
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THE Fourth International Congress for Applied Mechanics was held this year at Cambridge from July 3rd to July 9th, under the Presidency of Professor C. E. Inglis, O.B.E., F.R.S…
Abstract
THE Fourth International Congress for Applied Mechanics was held this year at Cambridge from July 3rd to July 9th, under the Presidency of Professor C. E. Inglis, O.B.E., F.R.S. At a conversazione at the Engineering Laboratory, by invitation of Professor Inglis and the staff of the University Engineering Department, members of the Congress were enabled to exhibit their own apparatus. A visit to the Cavendish Laboratory was also arranged for those especially interested in Atomic Physics.
Mostapha Tarfaoui and Samir Akesbi
The arrangement as well as the properties and the structure of the fibres within the yarn and the yarns within the fabric generate a complex mechanism of deformation in such…
Abstract
The arrangement as well as the properties and the structure of the fibres within the yarn and the yarns within the fabric generate a complex mechanism of deformation in such material. Therefore, intends to develop a theoretical model of the mechanical behaviour of the twill weave based on previous researches concerning the simplest plain weave. However, scaling up from the plain to the twill weave is not a direct transformation due to the non‐symmetry of the latter. The finite element method does not require simplifying hypotheses. Thus, it is possible to simulate different stresses, to determine the fabric response and to compare the behaviour of the various structures. This simulation requires the use of a realistic meshing of the basic cell and an accurate characterisation of the physical parameters of the material that composes the basic cell. Assuming the material to be elastic, the derived and, consequently, the discreet mathematical formulations of the problem have both been solved. The coefficients from those formulas are then used in the Modulef software. For each stage of the development, uniaxial, biaxial and perpendicular to the fabric plan, tensile tests have been simulated, as well as pure shear testing. The next step consisted of computing the Tresca and Von Mises stresses within the basic cell and the micro‐stress field within the basic cell components.
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The purpose of this paper is to use the variational iteration method (VIM) for studying boundary value problems (BVPs) characterized with dual solutions.
Abstract
Purpose
The purpose of this paper is to use the variational iteration method (VIM) for studying boundary value problems (BVPs) characterized with dual solutions.
Design/methodology/approach
The VIM proved to be practical for solving linear and nonlinear problems arising in scientific and engineering applications. In this work, the aim is to use the VIM for a reliable treatment of nonlinear boundary value problems characterized with dual solutions.
Findings
The VIM is shown to solve nonlinear BVPs, either linear or nonlinear. It is shown that the VIM solves these models without requiring restrictive assumptions and in a straightforward manner. The conclusions are justified by investigating many scientific models.
Research limitations/implications
The VIM provides convergent series solutions for linear and nonlinear equations in the same manner.
Practical implications
The VIM is practical and shows more power compared to existing techniques.
Social implications
The VIM handles linear and nonlinear models in the same manner.
Originality/value
This work highlights a reliable technique for solving nonlinear BVPs that possess dual solutions. This paper has shown the power of the VIM for handling BVPs.
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Satu Salmi, Martti Grönroos and Esko Keskinen
This article presents a model for police visibility and people's fear of crime. Survey data were collected from 3,245 adults and 977 teenagers in two typical Finnish…
Abstract
This article presents a model for police visibility and people's fear of crime. Survey data were collected from 3,245 adults and 977 teenagers in two typical Finnish neighborhoods. A four‐factor model including two visibility factors (patrol‐car‐related activities and police‐on‐foot activities) and two fear of crime factors (crimes against property and crimes against persons) was constructed by structural equation modeling. Respondents who perceived the police more often in on‐foot activities were less fearful of crimes against property. In the teenagers' group, the same effect was found in relation to crimes against persons. In both groups, seeing the police more in patrol‐car‐related activities resulted in increased fear of crimes against persons and property. Our results indicate that a simple act for the police, such as stepping out of the car every now and then, i.e. not only in crime‐related situations, has a positive impact on the fear of crime as expressed by the public.
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The paper aims to describe the design and manufacturing process of a tele‐operative urban search and rescue tracked robot and discuss the advantages of a proposed novel track…
Abstract
Purpose
The paper aims to describe the design and manufacturing process of a tele‐operative urban search and rescue tracked robot and discuss the advantages of a proposed novel track arrangement and other additional mechanisms, which help the robot to gain high manoeuverability on rough terrains.
Design/methodology/approach
Using a simplified static model, required torques are calculated and appropriate mechanisms and geometric dimensions are chosen. Next, stress distribution is analyzed in the parts, deploying both classic and numerical methods and to complete the procedure parts are fabricated and assembled together. The architecture of control system and the user interface is introduced. Finally, the robot is tested on a standard test arena and the results are compared with another similar search robot.
Findings
A tele‐operated rescue robot with considerable capabilities is designed and manufactured. The novel track arrangement and new rear arm's mechanism are tested and compared with a robot in the same class and higher performance is achieved on the evaluation.
Originality/value
Although the implemented locomotion mechanism is the common tracked type, adding the center tracks and arrangement of arms are original ideas which help the robot to gain high manoeuverability. The proposed rear arm's linkage mechanism generates a limited rotational path and has an acceptable strength for a robot working in rescue missions.
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The strength of personal selling lies in the fact that it allows for communicative interchange, a process more subtle but, at the same time, more hazardous than classical methods…
Abstract
The strength of personal selling lies in the fact that it allows for communicative interchange, a process more subtle but, at the same time, more hazardous than classical methods such as advertising, which rely on one‐way communication. In terms of efficiency, communicative interchange results in a reduction of reach losses; it is of primary importance in the marketing of commodities which have to be explained or demonstrated to the buyer and particularly, therefore, in industrial marketing and the marketing of services. It is recognised, however, that personal selling is a relatively expensive means of communication.The author undertakes a taxonomical review of the various constituents of the personal selling scene, analysing the tasks involved and the composition of the sales force. In the latter half of the monograph he selects certain sales force management problems of special importance to discuss in greater detail with regard to the optimisation of efficiency and job statisfaction.
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